Leukaemia can be either acute or chronic. The terms ‘acute’ and ‘chronic’ refer to how quickly the disease develops and progresses.
- Acute leukaemia develops and progresses quickly and therefore needs to be treated as soon as it is diagnosed. It affects very immature blood cells, preventing them from maturing properly.
- In chronic leukaemia a there is an accumulation of more mature but abnormal white cells. It can occur at any age, but is more common in older adults and is rarely seen in children.
Leukaemia can also be either myeloid or lymphoid. The terms myeloid and lymphoid refer to the types of cell in which the leukaemia first started.
- Myeloid: When leukaemia starts in cells which should eventually develop into platelets, red blood cells, granulocytes and monocytes, it is called 'myeloid', 'myelocytic', 'myelogenous' or 'granulocytic' leukaemia.
- Lympohoid: When leukaemia starts in cells destined to become lymphocytes (white blood cells), it is called 'lymphoblastic', 'lymphoid', 'lymphocytic', or 'lymphatic' leukaemia.